How the Media Got It Wrong on Bumblebee Decline Story

Whenever a scientific paper gets widespread press, it's usually not only because the topic resonates with the U.S. public but because the scientific journal publishing the study has made it available to reporters ahead of time so they can check facts, ask questions of the scientist and others in the field, and understand the science before they communicate it to the public.

When a reporter misses the opportunity to write the story when everyone else breaks the news, though, one of the best ways to find a fresh angle is to simply ask the scientist: What did we get wrong?

That's what I did after watching the flurry of headlines about the "sharp" "nosedive" in bumblebees, with four of eight species surveyed in "big trouble" because they are "rapidly dying off", with population declines "over 90%" due to a pathogen and "inbreeding".

The research matters because the U.S. is already suffering from losses of commercial honeybees, in part due to colony collapse disorder (itself possibly caused by pathogens and pesticides). And there has been growing concern that other native pollinators are in decline, too. Together, the loss of native and commercial pollinating insects could threaten food crops, as well as some native flowers and trees.

The lead researcher of the new bumblebee study is Sydney A. Cameron, an associate professor in the Department of Entomology at the University of Illinois - Urbana. I asked her if the coverage had missed anything or gotten anything wrong. Two things, she said by email:

The first addresses potential causal factors. We showed two ASSOCIATIONS with the declining populations: higher frequency of the pathogen Nosema bombi and also lower levels of genetic diversity. A Reuters piece stated that we conclude that a factor in decline is inbreeding. That was never stated and is incorrect.

The second issue concerns a careless use of numbers reported. We state that the the declining species have declined in RELATIVE ABUNDANCE BY AS MUCH AS 96%. But we do not say that all bumble bees have declined by 96%! The statement concerned relative abundance and the decrease in relative abundance ranged from 88%-96%, depending on the species.

"Relative abundance" means that the number of a particular species of bumblebee relative to the total number of bumblebees surveyed.

Cameron also had a couple small suggestions to improve the press release that Science, the journal that published his research, sent to reporters:

Low genetic diversity and high levels of a bee pathogen ail dwindling populations of North American bumble bees, a study finds. Bumble bees pollinate agricultural crops, such as tomatoes and berries, thanks to their large body size, long tongues, and high-frequency buzzing, which helps release pollen from flowers. In recent years, reports on the decline of local bumble bee populations have surfaced, raising ecological and economical concerns. To investigate the trends and causes of the purported bumble bee decline across the United States, Sydney A. Cameron and colleagues conducted a 3-year nationwide study of the changes in the distribution, genetic diversity, and health of eight species of North American bumble bees by comparing data from PAST museum records and CURRENT surveys. Within the last few decades, the relative abundance of four species has dropped FROM BETWEEN 88%-96%, suggesting die-offs further supported by shrinking geographic ranges. Compared with species of relatively stable population sizes, the dwindling bee species had low genetic diversity, potentially rendering them prone to pathogens and environmental pressures. Declining bee populations also had higher levels of infection with the bee pathogen Nosema bombi, which has been found IN European bumble bees, ALTHOUGH IN EUROPE THIS PATHOGEN IS NOT A FACTOR IN THE BUMBLE BEE DECLINE THEY HAVE WITNESSED. The findings warrant further research on the interplay of habitat, floral and nesting resources, disease, and climate to pinpoint the problems ailing the imperiled bees, according to the authors.